TY  - JOUR
AU  - Geselbracht, P.
AU  - Schneidewind, A.
AU  - Doerr, M.
AU  - Granovsky, S.
AU  - Rotter, M.
AU  - Loewenhaupt, M.
AU  - Scheerer, G. W.
AU  - Ren, Z.
AU  - Prokeš, K.
TI  - Magnetic phase diagram of CeCu 2 Ge 2 up to 15 T: On the route to understand field-induced phase transitions
JO  - Physical review / B
VL  - 95
IS  - 21
SN  - 2469-9950
CY  - Woodbury, NY
PB  - Inst.
M1  - FZJ-2017-04594
SP  - 214425
PY  - 2017
AB  - The features of the magnetic (H,T ) phase diagram of CeCu2Ge2 are similar to those of superconductingCeCu2Si2, but the nature of these phases and transitions is still controversial. For CeCu2Ge2 we present resultson electrical transport, thermodynamic measurements (magnetization, magnetostriction), and elastic neutrondiffraction for fields up to 15 T parallel to the [110] direction. Two magnetic phases AF1, AF2 and a third,yet unidentified ferrimagnetic phase AF3 exist below TN = 4.2 K and in fields up to approximately 26 T. Attemperatures below 2.5 K a first-order transition from AF1 to AF2 at around 7.8 T was found experimentally,characterized by a shift of the observed propagation vector from q1 = (0.285 − 0.285 0.543) to q2 = (0.34 −0.27 0.55). Above 12.5 T reflections belonging neither to the AF1 nor to the AF2 type were found. To interpretthe macroscopic measurements and neutron data a mean-field simulation with the McPhase program was carriedout, yielding a low-field double-q magnetic structure AF1 with q1± = (0.278 ± 0.278 0.556) that jumps toAF2 with q2± = (0.286 ± 0.286 0.545) at about 5 T (to be compared to the experimental value of 7.8 T). Thistransition is followed by a single-q structure AF3 with q3 = (0.28 0.28 0.56) at 10 T (as compared to 12.5 Tfrom experiment) that is stable up to saturation at 26 T. These calculations also reveal the principal dependenceof the experimental magnetization and susceptibility published earlier. The predicted single-q structure was notdetectable by neutrons because of limitations in the employed scattering geometry.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000404463800005
DO  - DOI:10.1103/PhysRevB.95.214425
UR  - https://juser.fz-juelich.de/record/834691
ER  -